1. Field of the Invention
The present invention relates to an assembled battery, in which electrode terminals of electrical cells are connected with a connection member such as a bus bar.
Priority is claimed on Japanese Patent Application No. 2010-221461, filed Sep. 30, 2010. The content is incorporated herein by reference.
2. Description of Related Art
In an assembled battery, an electrode terminal of an electrical cell and a connection member such as a bus bar are connected to each other by using a bolt or by welding the bus bar to the electrode terminal.
In Japanese Patent Application Laid-Open No. 2006-60181 (for example, see FIG. 23 in the Laid-Open), there are a wiring connection portion as an electrode terminal having a slit formed in a minus (−) or plus (+) shape in the plan view and a wiring plate as a connection member for an electrode terminal to fit into the slit.
In Japanese Patent Application Laid-Open No. 2003-109578 (for example, see FIG. 7 in the Laid-Open), there is a connection terminal connected to an electrode terminal having a tapered shape of which the diameter decreases toward the front end. The connection terminal having a slit includes a conductive tapered pipe having cylindrical shape and a resinous portion having a male screw portion. Then, when the connection terminal is fastened by a resinous insulating cap having a female screw portion, the connection terminal is tucked inward in the radial direction, and the conductive tapered pipe is fastened and fixed to the electrode terminal.
However, in the structure between the electrode terminal and the connection terminal in the above-described related art, there is a problem that a bolt is loosened due to vibration or the like in use. For this reason, in the structure using a bolt, the connection may not be reliably maintained for a long period of time. On the other hand, in the structure using the welding, when the members are once fixed to each other, the members cannot be separated from each other. Therefore, a crack may occur in the welding portion due to vibration.
And as to the wiring connection portion disclosed in Japanese Patent Application Laid-Open No. 2006-60181, the wiring plate is fitted to the slit. Therefore, it is difficult that the wiring connection portion and the wiring plate are connected to each other. It means that the wiring plate may be separated from the wiring connection portion due to vibration or the like in use.
Furthermore, since the connection terminal disclosed in Japanese Patent Application Laid-Open No. 2003-109578 is formed in a tapered shape of which the diameter decreases toward the insulating cap, the connection terminal may be separated from the insulating cap due to vibration. Also, since the screw structure is adopted in the connection terminal disclosed in Japanese Patent Application Laid-Open No. 2003-109578, the screw may be loosened due to vibration. Thus, the problem regarding the bolt has not be solved.